Strengths of HRM
One technology, multiple benefits
HRM has several unique advantages compared to other methods of analysis, no matter what your application. Click on the following links and discover the benefits of this versatile technology.
Advantages over tranditional real-time PCR methods
HRM-based methods provide greater flexibility as there is no requirement for fluorescently-labeled detection probes (such as TaqMan probes) — simplifying assay design. Detection of previously unknown variants is straightforward and it is possible to simultaneously detect multiple SNPs or mutations in the same PCR reaction.
Specific and accurate detection method
PCR products can be discriminated according to sequence, length, GC content, or strand complementarity, down to single base pair differences. Previously unknown and even complex sequence variations — as seen in challenging genotyping applications — can be readily detected and characterized in an easy and straightforward way (see figure Successful genotyping of an A/T class IV SNP using the Type-it HRM PCR Kit).
Fast screening method for unknown mutations
Due to the high level of sensitivity afforded by HRM technology, it can be employed as an initial screen for samples suspected of harboring polymorphisms or mutations (see figure Successful mutation screening). This would reduce the number of samples that need to be investigated further.
Nondestructive analysis method
The PCR product can be subjected to repeated melt analyses and it can be further used in downstream applications such as cloning or sequencing.
Closed tube method – minimal contamination
Cross-contamination is minimized as HRM is a closed-tube technique. Unlike other genotyping methods such as denaturing gradient gel electrophoresis (DGGE), HRM does not require the use of hazardous reagents such as acrylamide, formamide, and ethidium bromide.
HRM is cost effective as there is no requirement for fluorescently-labeled detection probes. All you need is a pair of standard oligonucleotides, PCR chemistry comprising of an HRM-compatible dye, and an instrument capable of monitoring the fluorescence decrease upon temperature increase with high thermal and optical precision. A cost-effective solution is the use of a real-time cycler that ensures high temperature uniformity (typically better than 0.1°C), together with dedicated HRM software.
HRM is a versatile method that can be used in a large variety of applications. HRM technology addresses a wide range of genetic analyses such as mutation detection and mutation screening to analyze:
- Point mutations
- Multiple mutations
These analyses can be performed for both known and unknown mutations.
Genetic variations that can be analyzed by HRM:
- CpG methylation status
- Strain variations of microbes, plants, and animals
- VNTRs (mini- and microsatellites)
- Loss of heterozygosity
- Genome polyploidy
- CNVs/gene copy number variations